Quality control process flowchart

How it works

1. Name your real inspection points

   Replace the Incoming, In-process and Final branches with the points you actually operate — goods-in, first-off, patrol, final, pre-despatch — and give each one its own specification and reaction plan. If you only inspect at goods-in, delete the other branches rather than leaving undrawn steps that people assume happen.

2. Attach the real sampling plan

   Record the standard, AQL, inspection level, lot size and the accept and reject numbers on the sampling step, plus what switches you to tightened or reduced inspection. ISO 2859-1 or ANSI/ASQ Z1.4 cover attribute sampling; state 100 percent inspection explicitly where that is what you do.

3. Put the specification and method on the test step

   Name the specification and its revision, the approved test method, and who is competent to run it. A test step that does not record which revision applied is the step that fails an investigation two months later.

4. Write your out-of-specification rules into the branch

   Decide who may invalidate a result, how many retests are permitted and on which sample, and what evidence closes the laboratory phase. Without those written down, the retest loop turns into testing until a passing number appears.

5. Name the review board and its authority

   List who sits on the material review board, who may authorise a concession, and when the customer has to be told before nonconforming product is accepted. Add a value or risk threshold if the board only convenes above one.

6. Decide what gets trended, and where it is reviewed

   Pick the fields the trend needs — defect code, supplier, line, shift, batch — and name the forum that looks at them. Recording results with no review step means the process ends in a filing cabinet rather than in a corrective action.

Frequently asked questions

What are the steps in a quality control process?

Seven, in this order: identify which inspection point applies (incoming, in-process or final); draw a sample per the sampling plan; inspect it; test it against the specification; decide whether the results conform; release the batch or route it into nonconforming control; and record the results so they can be trended. The decision in the middle is the process. Everything before it exists to make that decision reliable, and everything after it exists to make it traceable.

What is the difference between quality control and quality assurance?

Quality control is product-facing and after the fact: it inspects and tests output and decides whether this batch conforms. Quality assurance is system-facing and preventive: procedures, training, supplier approval, calibration, validation and audit, all aimed at making conformance likely in the first place. In this chart the QC inspector and QC lab lanes are quality control; the quality manager's release authorisation, review board and trending steps are where control feeds back into assurance.

What happens when a test result is out of specification?

It triggers an investigation, not an immediate rejection. The first phase looks at the laboratory — method, dilution, calculation, instrument, analyst — because an invalid number should not condemn conforming product. The original result stays on file whatever is found, and retesting happens under a written plan rather than repeatedly until a passing number appears. If no laboratory error is found, the result stands and the batch becomes a nonconformance: reported, quarantined and taken to the review board. Regulated manufacturers formalise this split (the FDA's out-of-specification guidance separates a laboratory phase from a full investigation), but the logic holds in any factory.

What is the difference between rework, concession and scrap?

They are the three dispositions a material review board can give nonconforming material. Rework brings it back into full conformance and has to be re-inspected and retested — in this chart the rework branch loops back to the sampling step, never straight to release. A concession is documented acceptance of product that still does not meet the requirement; ISO 9001:2015 clause 8.7 calls this acceptance under concession and expects the authorising person and the record to be identified, with the customer informed where the requirement is theirs. Scrap disposes of the material and writes it off, with the reason recorded so the cost appears in the trend rather than disappearing into stock adjustments.